The invention relates to bar holders and feeders for machine tools.
Our U.S.A. patent application Ser. No. 187,985, now U.S. Pat. No. 3,802,689, discloses a bar holder to hold bar stock material to be fed to a machine tool and our U.S.A. patent application Ser. No. 164,403, now U.S. Pat. No. 3,782,593, discloses loading means for loading bar stock material into such bar holders. Such loading means merely allows a bar to fall under gravity into the bar holder to lie in a position such that it will be contained in the bar holder when the bar holder is subsequently closed.
Various means have been proposed for feeding bar from bar holders through the collets of machine tools but generally such means are too slow for optimum operation and/or are not capable of feeding bar of non-round section, for example hexagonal or square section bar.